Portable power-driven hand-tool.



E. F. SMITH. PORTABLE POWER DBIVEN HAND TOOL.

' APPLICATION FILED SEPT. '71, 1911. 1,024, 1 5 l 7 Patented A111223 WzL/5255555- EDWARD'F. SMITH, OF CINCINNATI, OHIO, ASSIG'NOR TO THE SMITH ELECTRIC TOOL C0., 0F CINCINNATI, OHIO, A CORPORATION OF OHIO.

PORTABLE i?(diurnal)larven HAND-troon.

Specicatiion of Letters Patent. Application inea september 7', 1911.

Patented Apr. 23, 1912. serial no. y 648,054.

To all whom tt may concern:

Be it known that I, EDWARD F. SMITH, a citizen of the United States, and a resident of Cincinnati, inthe county of Hamilton and State of Ohio, have invented a certain new and useful Portable Power-Driven Hand-Tool; and I do declare the following to `be a clear, full, and exact description thereof, attention being called to the drawingwhich accompanies -this application and forms a part thereof.

This invention relates to improvements in portable, hand-manipulated tools driven by power and in which the action of the tool involvesrotation.

The tool proper which directly effects the particularly work to be done may be a drill,

reamer, boring-bit or other tooloperating by rotation. It may also be a screw-driver bit in connection with which the invention is shown-and described. l

The invention consists of the .particular construction hereinafter `descrlb'ed and pointed out in the claims and illustrated inthe accompanying drawing, in which-:

Figure 1,shows the tool 1n side elevation, F ig. 2, is a longitudinal sectlon of the same.

Fig. 3, is an enlarged end-view of the tool socket. Fig. 4, shows in perspective -yiewa tool-bit, it being a screw-drlver-bit 1n thls case; `Fig. 5, illustrates 1n a perspectlve view of reduced size manipulation of the tool. Fig. 6, shows in side-elevation a modified form of the tool.l

8 indicates the shank of the tool-bit which -is fitted'` to the bore of the bit-socket 9. It is tbe done 'and in Athis' case driver as shown at' 13.

held therein so as to rotate therewith by any suitable means which might be a set-screw. A clamping-nut 10, applied to the outer end of the socket may also be used. The bore of this nut or' the threaded end which it engages is slightly tapered so that when the nut is screwedhome the end of the socket is compressed, the same being slotted for the purpose as shown at 11 in Fig. 3. To prevent slipping ofthe bit, its inner end may be shaped as shown at.12 in Fig. 4, the inner end of the socket-borel being shaped complementary thereto. The outer end of the bit is shaped according to the work to forms a screw- 14 is the shaftwhich receives the power. It transmits the same to the tool-socket by means of the opposite surfaces of two friction-elements kept normally apart by a spring 15 which, when pressure is applied, ylelds and permits contact of the frictionelements. These elements consist of a cupshaped, or internal friction cone 16 on the bit-socket and a complementary friction cone 17 on shaft 14. Shaft 14 extends beyond the narrow end of the cone and is fitted into a bore 18 in the inner end of the bit-socket for guidance of the friction elements. A cap 19 holds the tool-parts to each other 'by closing the open end of cup 16 and by confining cone 17, this being done without interfering with the movement for adjusting the friction elements. Cap 19 also forms an additional supporting guide for shaft' 14 by being formed to contain a bearing for the same. It will now be seen, when pressure yis applied in a manner caus- 111g the friction surfaces to contact with each other, that the power of shaft 14 is transmitted to the bit-socket and causes the same and the tool-bit carried by itto rotate.

The rotation of the tool-bit is at all times under perfect control as to rate of speed and may be varied by varying the pressure `whereby the friction-elements are held in Contact. One of the opposite friction surfaces is preferably covered with leather to promote ready contact. The power is instantly taken off from the bit-socket and bit as soon as the pressure is relieved. Connection of the power to shaft 14 is made at its end which projects beyond cap 19. In the form shown in Fig. 6, this end may be connected to a portable motor.

As shown in Figs. l1, 2 and 5, a beveled gear-Wheel 2l is mounted on it and driven by a complementary gear-.element 22. This latter is mounted on a shaft 23, supported in a gear oase 24. The case is carried on shaft 14. Power is received from a flexible shaft 2 5 connected to shaft 23.

The manipulation ofthe tool is shown in Fig. 5.` One hand grasps handle 26 secured to the casing and the other takes hold of `a hand-hold 27, loosely carried on the bitsocket, it being held in place by nut 10 or by a collar 28. Pressure is applied by action on handle 26 and varied according to conditions. A screw for instance may be slowly started by application of light pressure and rapidly driven home by increasing the pressure. Rotation is stopped by removing the pressure, and this 1s done instantly since there is nothing which holds the friction-elements positively in engagement. Nothing is done to the power-connected elements which operate without interruption. The implement as shown in Fig. 6, may also be used in connection with a stationary tool as for instance it ma be attached to the chuck of a lathe or ril1- press. In that case the pressure necessary to effect rotation of the bit is applied at hand-hold 27.

Having described my invention, I claim as new:

l. In a portable, power-driven hand-tool, the combination of a cylindrical bit-socket adapted to receive a tool-bit at one end and provided with an internal friction cone at its other end which has a shaft-bearing in its deepest part, a hand-hold loosely mounted upon the bit-socket, a ca fitted to close the internal cone and provi ed with a shaft bearing in its center, a driving shaftfslidably fitted to the two shaft-bearings mentioned, a friction cone mounted on this shaft in a position to be within the internal friction cone, means to rotate this shaft, a spring supported on the shaft and positioned between the two cones to keep them yieldingly apart and a handle at the outer end of the shaft to hold the tool and to adjust the shaft lengthwise in its bearings and with reference to the internal friction cone.

2. In a portable hand-tool, the combination of a gear-case, a shaft mounted in the same, a gear-wheel on this shaft and 'within the case, a pinion supported in this latter l 3. In a portable, power-driven hand tool,

the combination of a bit-socket adapted to receive a tool-bit at one end and provided with' an internal friction-cone at its other end, a cap fitted to close this cone and a handhold loosely mounted upon the bit# socket, a driving-shaft upon which this in-` ternal friction cone and its cap are slidably fitted, supporting-means for this shaft and means to rotate it, a friction-cone mounted 'on this shaft in a position to be within .the .internal friction-cone, and a spring between the two cones to kee them apart, but adapt*- led to yield when eit er of the cones is moved with reference to the other one, to permit them to contact with each other.

In testimong whereof, I hereunto affix my signature vin t e presence of two witnesses.

EDWARD F. SMITH.

Witnesses C. SPENGEL, T. LE BEAU. 

